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41.
ZnS thin films were deposited on soda lime glass and aluminum substrates by close-spaced sublimation technique. The change in composition, structural and optical properties of the films was investigated as a function of the substrate temperature. The deposited films were stoichiometric and crystalline in nature having cubic structure oriented only along (1 1 1) plane. The energy band gap of the films deposited at the substrate temperature of 150, 250 and 350 °C was 3.52, 3.58 and 3.63 eV respectively. These films were then bombarded with 2-10 keV energy pulsed Ar+ beam and their electron yield was determined from impinging ion and emitted electron currents. The electron yield of ZnS films was much high as compared to the metals. The electron yield of ZnS films increased with energy of the incident ion and got saturated at about 8 keV. The most important result of this study was that the electron yield of ZnS films having same composition was different. Monte Carlo simulations performed to interpret these experimental findings showed that the dissimilar electron yields of ZnS films is due to the combined effect of energy band gap, surface barrier potential and density of the films. 相似文献
42.
43.
The phosphorescence bioimaging and sensing applications of Iridium (III) complexes, in particular to subcellular organelle staining as well as sensing of biologically important analytes, have been reviewed here. The bioimaging applications of the metal complexes provide an attractive alternative to fluorescent organic compounds in the construction of biosensors and biolabels because of having certain advantages. 相似文献
44.
Alharbi F. F. Nisa Mehar Un Hassan Hassan Mohamed Ahmed Manzoor Sumaira Ahmad Zahoor Abid Abdul Ghafoor Aman Salma Ashiq Muhammad Naeem El-Nasser Karam S. Taha Taha Abdel Mohaymen 《Journal of Solid State Electrochemistry》2022,26(10):2171-2182
Journal of Solid State Electrochemistry - Metal sulfide and oxides have drawn interest as economical substitutes to noble metal catalysts due to their ability for oxygen evolution reaction (OER)... 相似文献
45.
Abid Abdul Ghafoor Manzoor Sumaira Ahmad Zahoor Hussain Dilshad Mersal Gaber A. M. El Azab Islam H. Elnaggar Ashraf Y. El-Nasser Karam S. Taha T. A. Ashiq Muhammad Naeem 《Journal of Solid State Electrochemistry》2022,26(11):2401-2410
Journal of Solid State Electrochemistry - In the recent work, the scheelite-type ABO4 compound (A = Nd and B = Os) is synthesized via a hydrothermal route directly... 相似文献
46.
Sumaira Khan 《Talanta》2009,80(1):158-220
A separation/preconcentration of aluminum (III) (Al3+) has been developed to overcome the problem of high matrix species, which may interfere with the determination of trace quantity of Al3+ in natural water samples. The separation of Al3+ in water samples was carried out from interfering cations by complexing them with 2-methyle 8-hyroxyquinoline (quinaldine) on activated silica. Whereas the separated trace amounts of Al3+ was preconcentrated by cloud point extraction (CPE), as prior step to its determination by spectrofluorimetry (SPF) and flame atomic absorption spectrometry (FAAS). The Al3+ react with 8-hydroxyquinoline (oxine) and then entrapped in non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of separation/preconcentration of Al3+ was checked by certified reference material of water (SRM-1643e). After optimization of the complexation and extraction conditions, a preconcentration factor of 20 was obtained for Al3+ in 10 mL of natural water samples. The relative standard deviation for 6 replicates containing 100 μg L−1 of Al3+ was 5.41 and 4.53% for SPF and FAAS, respectively. The proposed method has been applied for determination of trace amount of Al3+ in natural water samples with satisfactory results. 相似文献
47.
M. Hassan R.S. Rawat P. Lee S.M. Hassan A. Qayyum R. Ahmad G. Murtaza M. Zakaullah 《Applied Physics A: Materials Science & Processing》2008,90(4):669-677
Nanocrystalline multiphase titanium oxycarbide (TiCxOy) thin films composed of TiC2, TiO0.325, Ti2O3 and graphitic carbon have been deposited on titanium substrates, using energetic carbon ions delivered by the UNU/ICTP and
the NX2 plasma focus devices operated at different repetition rates. X-ray diffraction (XRD) patterns of the nanocomposite
films reveal the relative transformation of various oxide and carbide phases accompanied by the suppression of the TiC2 phase when the energy flux of the ion beam and the repetition rate are increased. A field emission scanning electron microscope
(FESEM) with an energy dispersive X-ray spectroscopy (EDS) attachment reveals a non-porous microcrack-free nanocrystalline
granular surface morphology of the composite films with uniform carbon distribution. X-ray photoelectron spectroscopy (XPS)
confirms the formation of oxycarbides (TiCxOy) along with significant carbon adsorbate. Raman studies of the films also verify the relative phase transformation in the
TiCxOy nanocomposite by tuning the deposition parameters. The Vickers microhardness of the sample surface is improved more than
400%.
PACS 52.59.Hq; 52.77.Dq; 68.55.Jk; 81.15.-z; 81.65.Lp 相似文献
48.
Abid Abdul Ghafoor Ashiq Muhammad Faheem Alfryyan Nada Manzoor Sumaira Nisa Mehar Un Al-Buriahi M. S. Alomairy Sultan Alrowaili Z. A. Ashiq Muhammad Naeem 《Journal of Solid State Electrochemistry》2022,26(10):2107-2118
Journal of Solid State Electrochemistry - The discovery of highly active and cost-effective materials capable of catalyzing the oxygen evolution reaction (OER) is essential for water splitting. In... 相似文献
49.
Nadeem Muhammad Muhammad Zia-ul-Haq Amjad Ali Sumaira Naeem Azeem Intisar Dongxue Han Hairong Cui Yan Zhu Jia-Lun Zhong Abdul Rahman Binnian Wei 《Arabian Journal of Chemistry》2021,14(3):102972
Ion chromatography (IC) is a well-known technique for trace determination of inorganic ions and small organic acids. Recently, it has also appeared as a promising alternative to reverse phase chromatography for the determination of polar pesticides and pharmaceutical drugs in various sample matrices. Therefore, this study aims to provide a comprehensive overview of the application of IC coupled to fluorescence (FLD) or UV detector for the determination of pesticides and pharmaceutical drugs in samples from all walks of life. Apart from advantages and limitations, a short comparison of IC-FLD/UV with other techniques especially reverse-phase chromatography was drawn to envision future research efforts in this direction. Finally, several related areas such as IC hyphenation with different detectors (spectroscopic and spectrometer), miniaturization, automation, green chemistry, mobile phase, column, sample preparation, etc., were discussed to highlight its application for the determination of a wide range of analytes in the complex sample matrix. 相似文献
50.
Wasim Ul Bari Najeeb Ur Rehman Ajmal Khan Sobia Ahsan Halim Ye Yuan Mark A.T. Blaskovich Zyta M. Ziora Muhammad Zahoor Sumaira Naz Riaz Ullah Amal Alotaibi Ahmed Al-Harrasi 《Molecules (Basel, Switzerland)》2021,26(7)
In the study, two novel compounds along with two new compounds were isolated from Grewia optiva. The novel compounds have never been reported in any plant source, whereas the new compounds are reported for the first time from the studied plant. The four compounds were characterized as: 5,5,7,7,11,13-hexamethyl-2-(5-methylhexyl)icosahydro-1H-cyclopenta[a]chrysen-9-ol (IX), docosanoic acid (X), methanetriol mano formate (XI) and 2,2’-(1,4-phenylene)bis(3-methylbutanoic acid (XII). The anticholinesterase, antidiabetic, and antioxidant potentials of these compounds were determined using standard protocols. All the isolated compounds exhibited a moderate-to-good degree of activity against acetylcholinesterases (AChE) and butyrylcholinesterase (BChE). However, compound XII was particularly effective with IC50 of 55 μg/mL (against AChE) and 60 μg/mL (against BChE), and this inhibitory activity is supported by in silico docking studies. The same compound was also effective against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) radicals with IC50 values of 60 and 62 μg/mL, respectively. The compound also significantly inhibited the activities of α-amylase and α-glucosidase in vitro. The IC50 values for inhibition of the two enzymes were recorded as 90 and 92 μg/mL, respectively. The in vitro potentials of compound XII to treat Alzheimer’s disease (in terms of AchE and BChE inhibition), diabetes (in terms of α-amylase and α-glucosidase inhibition), and oxidative stress (in terms of free radical scavenging) suggest further in vivo investigations of the compound for assessing its efficacy, safety profile, and other parameters to proclaim the compound as a potential drug candidate. 相似文献